1. Field of the Invention
This invention relates generally to combustors, and, more particularly, to catalytic combustors for gas turbine power plants.
2. Description of the Prior Art
Blades in high temperature turbines normally must be cooled internally to withstand the operating temperatures of the turbine. This is because a high motive fluid temperature is necessary for the high efficiency, and the blades may fail due to the high stresses developed within them if not properly cooled. With such internal blade cooling the root area of each blade will not necessarily be at a temperature lower than the remainder of the blade even though the root area is the most highly stressed area of each blade. The life of the blade root is considerably less than that of the remainder of the blade. It is therefore desirable to control the motive fluid temperature profile so that the midsection of the blade generally is exposed to the peak temperature of the hot motive fluid while the root portion is exposed to a much cooler motive fluid which is emanating from the combustor.
Dilution air is ordinarily injected into combustors through an array of orifices in the combustor shell, to yield a desirable motive fluid or an air temperature distribution at the combustor outlet. The combustor air is often diluted to reduce NOx contents of the combustion products and to reduce smoke. Environmental requirements make it mandatory that visible smoke be eliminated and that harmful products of combustion be minimal. This is accomplished by insuring complete combustion, and regulating temperatures and dilution air or injected steam in the combustor. Prior art that exemplify attempts at these goals are U.S. Pat. Nos. 3,498,055; 3,593,518; 3,742,706; and 3,747,336.